Intraoperative fractures of the femoral diaphysis in hip arthroprosthesis surgery.

The authors reviewed 14 cases of fracture of the femoral diaphysis which occurred during 602 hip arthroprosthesis operations. They attempted to ascertain the role of local and general factors in this complication. In 5 cases there was obvious structural alteration in the upper third of the femur with decreased bone resistance; in 5 cases there was abnormal morphology of the diaphyseal canal (morphological incongruence) due to hip dysplasia or previous osteotomy; in 3 cases there was marked dimensional incongruence between the prosthetic stem and the medullary canal and in the remaining case abnormal morphology of the medullary canal was associated with dimensional incongruence. From an analysis of the cases it emerged that complete fractures in cemented arthroprostheses negatively influenced the long-term results while fractures occurring in arthroprostheses with biological fixation do not significantly modify the normal progression. Finally, the authors stress that a careful preoperative evaluation of the radiographs may considerably reduce the incidence of this complication.